Cognitive neuropsychologists apply the methods and models of cognitive psychology to study disorders resulting from brain damage. Up to now, the concerns have been mostly of a theoretical nature and have had little to do with the therapeutic management of patients. This proposal is aimed at rectifying this situation. Part 1 of the Research Plan deals with acquired aphasia. Recent psycholinguistic studies indicate that some aphasic patients suffer from an inability to assign thematic roles (e.g., agent, patient) to syntactic functions (subject, object) in accordance with lexically-stated mapping rules. This "mapping" impairment has serious consequences for producing and comprehending sentences and underlies at least some aspects of the "agrammatism" of the Broca-type aphasic. A study is therefore proposed to evaluate an original treatment program aimed at strengthening the mapping operations in patients who show the agrammatic pattern in speaking and/or comprehending sentences. The second study is Part 1 proceeds on the assumption that the paraphasia-filled speech of the fluent aphasic is subject to analysis on the model of "slips-of-the-tongue". A method is proposed for classifying patients' "slips" and for interpreting the resulting pattern in accordance with a theory of sentence planning. Some preliminary treatment techniques are proposed which have the goal of modifying the size of the planning units and the speech rate, parameters which, on the theory, exert a critical influence on both the frequency and the character of speech errors. It is possible to view slips-of-the-tongue as a special case of "errors of action" and indeed, more general theories of action have been proposed that speak to the origin of non-verbal, as well as verbal slips. In Part II of the Research Plan, such a theoretical perspective is brought to bear on the problems in planning and executing routine activities (ideational apraxia) shown by patients with traumatic brain injury. An observational study is proposed that involves videotaping selected patients in the performance of routine morning activities and classifying their errors according to an original taxonomic scheme. A proposed diary study assesses whether this scheme reliably classifies the action slips recorded by non-brain damage individuals. Comparisons between the two error corpora are expected to generate hypotheses as to the origin of patients' errors within the conceptual system for action and lead to future treatment studies aimed at remediating or circumventing the underlying disturbance.